Let's go to an obviously loved game, the Call of Duty series. Mainly focusing on my own opinion I have to say I am becoming more and more disappointed.
To give the basic information to those who don't know much of the series there are two developers of the game under one publisher. The developers being TreyArch and Infinity Ward, although the later has recently been sued and the viability of the company is questionable.
I personally believe TreyArch makes less than mediocre games and that the most recent installment to the series (Black Ops) was awful. Yes, I admit I clocked in 24 hours of play time, but for a $60 release price, not worth my money. I found myself crawling back to earlier installments in the series, mainly created from Infinity Ward or just ignoring the series.